Contradiction with John 5:14
In John 5:14, Jesus warns the man he healed to "sin no more," implying that sin can cause sickness, whereas Mark 1:31 makes no mention of sin or repentance in relation to the healing.
John 5:14: Afterward Jesus findeth him in the temple, and said unto him, Behold, thou art made whole: sin no more, lest a worse thing come unto thee.
Contradiction with Matthew 13:58
In Matthew 13:58, Jesus did not perform many miracles due to people's unbelief, whereas in Mark 1:31, He healed Peter's mother-in-law without any mention of her belief.
Matthew 13:58: And he did not many mighty works there because of their unbelief.
Contradiction with Matthew 8:4
In Matthew 8:4, Jesus instructs the healed leper to tell no one but to show himself to the priest, while in Mark 1:31, there is no such instruction given post-healing.
Matthew 8:4: And Jesus saith unto him, See thou tell no man; but go thy way, shew thyself to the priest, and offer the gift that Moses commanded, for a testimony unto them.
Contradiction with Luke 4:41
Luke 4:41 mentions that Jesus rebuked demons and would not allow them to speak when casting them out, whereas in Mark 1:31, there is no indication of any demonic presence or Jesus rebuking anything in the healing act.
Luke 4:41: And devils also came out of many, crying out, and saying, Thou art Christ the Son of God. And he rebuking [them] suffered them not to speak: for they knew that he was Christ. [to speak...: or, to say that they knew him to be Christ]